Proximal humeral stabilization system

ABSTRACT

Devices, systems, and methods for bone stabilization, especially proximal humeral stabilization. The stabilization system may include a bone plate having an elongated portion extending along a longitudinal axis and an enlarged head portion extending from the elongated portion. The stabilization system may include an intramedullary nail having an upper portion and a lower portion extending from the upper portion, the upper portion and the lower portion including a plurality of holes. A plurality of fasteners may be configured to extend through one or more of the plurality of through holes in the bone plate and/or one or more of the plurality of holes in the intramedullary nail and into the bone. The plate and nail may each be used alone or in combination together to stabilize a fracture in a long bone, such as a humerus.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/476,168, filed Mar. 31, 2017, which is acontinuation-in-part of U.S. patent application Ser. No. 15/238,767,filed Aug. 17, 2016, which claims priority to U.S. provisionalapplication No. 62/210,680, filed Aug. 27, 2015, which are herebyincorporated by reference in their entireties for all purposes.

FIELD

The present disclosure relates to surgical devices and stabilizationsystems, for example, for trauma applications, and more particularly,for stabilization of proximal humeral fractures.

BACKGROUND

Bone fractures are often repaired by internal fixation of the bone, suchas diaphyseal bone, using one or more plates. The plate is held againstthe fractured bone with screws, for example, which engage the bone andheads which provide a compressive force against the plate. The plate andbone are thus forced against each other in a manner that transfers loadprimarily between a bone contacting surface of the plate and the bonesurface to reinforce the fractured bone during healing. This manner ofplating generally creates relatively low stress concentration in thebone, as there may be a large contact area between the plate and thediaphyseal bone surface permitting transfer of load to be dispersed.There may be a desire to use locking screws, non-locking screws, or acombination of both that are able to dynamically compress the bone. Ofcourse, the designs of the plates, types of screws, and locking and/ornon-locking capabilities may vary based on the location and type offracture.

The three long bones of the upper extremity are the humerus, radius, andulna. In the case of proximal humerus fracture fixation, plating of thelateral bone surface may be desirable. In some cases, plating alone maylead to humeral head collapse during healing, and the addition of anallograft fibular strut inside of the intramedullary canal and insertedthrough the fracture site may prevent head collapse. There remains aneed, however, for improved plating systems and/or intramedullarysystems that provide appropriate stabilization to the humerus.

SUMMARY

To meet this and other needs, devices, systems, and methods of bonestabilization are provided, for example, for humerus stabilization. Theproximal humerus stabilization systems may include one or more platesand one or more fasteners. The proximal humerus stabilization systemsmay also include an intramedullary nail and one or more fastenersextending therethrough. The plate and nail may each be used alone or maybe used in combination together to stabilize a long bone, such as ahumerus. Although generally described with reference to the humerus, itwill be appreciated that the stabilization systems described herein maybe used or adapted to be used for the fixation of other long bones aswell, such as the femur, tibia, etc.

According to one embodiment, a stabilization system includes a boneplate, an intramedullary nail, and a plurality of fasteners. The boneplate comprises an elongated portion extending along a longitudinal axisand an enlarged head portion extending from the elongated portion, thebone plate comprising a plurality of through holes. The intramedullarynail comprises an upper portion and a lower portion extending from theupper portion, the upper portion and the lower portion including aplurality of holes. The intramedullary nail may be configured such thatthe lower portion of the intramedullary nail is received in anintramedullary canal and the upper portion is received in the head ofthe humerus. The fasteners are configured to extend through one or moreof the plurality of through holes in the bone plate and one or more ofthe plurality of holes in the intramedullary nail and into the bone.

The fasteners may include locking fasteners (e.g., configured to lock tothe plate and/or the intramedullary nail), non-locking fasteners (e.g.,configured to provide dynamic compression of the bone), polyaxialfasteners (e.g., configured to be inserted at a plurality of angles ortrajectories), fixed angle fasteners (e.g., configured to be inserted ata fixed angle or trajectory), or any other suitable fasteners known inthe art. The plurality of through holes may comprise first and secondpolyaxial openings, and the plurality of fasteners may comprisepolyaxial calcar screws configured to be received in the first andsecond polyaxial openings, and configured to be aimed at a calcar regionof a proximal humerus. The plurality of through holes may comprise aplurality of fixed angle openings positioned on the enlarged headportion of the plate, and the plurality of fasteners may comprise fixedangle, locking screws configured to be received in the fixed angleopenings and the upper portion of the intramedullary nail and configuredto be aimed at a humeral head. The plurality of through holes maycomprise a plurality of elongated slots positioned on the elongatedportion of the plate, and the plurality of fasteners may comprise atleast one polyaxial screw configured to be received in at least one ofthe plurality of elongated slots and within one of the plurality ofholes in the lower portion of the intramedullary nail to permit dynamiccompression of the bone. In some instances, the locking fasteners mayinclude fasteners having self-forming threads on a head portion of thefasteners, which are configured to lock to at least one of the pluralityof through holes on the plate.

According to another embodiment, a stabilization system configured tostabilize a humerus includes a bone plate, a plurality of polyaxialcalcar fasteners, a plurality of fixed angle, locking fasteners, and atleast one polyaxial, non-locking fastener. The bone plate includes anelongated portion extending along a longitudinal axis and an enlargedhead portion extending from the elongated portion. The bone platecomprises first and second polyaxial openings, a plurality of fixedangle openings positioned on the enlarged head portion of the plate, anda plurality of elongated slots positioned on the elongated portion ofthe plate. The plurality of polyaxial calcar fasteners may be configuredto be received in the first and second polyaxial openings and configuredto be aimed at a calcar region of the humerus. The plurality of fixedangle, locking fasteners may be configured to be received in theplurality of fixed angle openings, respectively, and configured to beaimed at a humeral head of the humerus. The polyaxial, non-lockingfastener may be configured to be received in one of the plurality ofelongated slots to permit dynamic compression of the bone and configuredto be aimed at a shaft of the humerus.

According to another embodiment, a stabilization system includes animplant and a plurality of fasteners. The implant has an upper portionand a lower portion, the upper portion configured and dimensioned to becylindrical and the lower portion extending from the upper portion, theupper portion and the lower portion including a plurality of holes. Thelower portion may be positioned in an intramedullary canal and the upperportion may be positioned in a humeral head. The plurality of fastenersmay be configured to be received by the plurality of holes of the upperand lower portions of the implant.

According to yet another embodiment, one or more methods of installing astabilization system may include aligning a bone plate to a lateralsurface of the humerus, inserting an intramedullary nail such that thenail is at least partially received in the head of the humerus and theintramedullary canal of the shaft, and inserting one or more fastenersthrough the bone plate, through the intramedullary nail, and into thebone to stabilize the humerus and repair the fracture. Before thefasteners are inserted, one or more pilot holes may be pre-drilled andthe bone plate and/or intramedullary nail may comprise one or more drillguides to aid in aligning the appropriate trajectories of the respectivebone fasteners.

According to another embodiment, a stabilization system for stabilizinga bone includes a bone plate and a drill guide. The bone plate includesan elongated portion extending along a longitudinal axis and an enlargedhead portion extending from the elongated portion. The bone platecomprises a plurality of through holes. The drill guide is attached tothe enlarged head portion of the bone plate. The drill guide has aplurality of openings that correspond to the plurality of through holeson the bone plate. The drill guide is secured to the bone plate with afastener extending through an opening in the plate. The opening mayinclude a flange so that the thread of a single pitch screw can start inthe drill guide and compress the drill guide to the plate.

Also provided are kits for the stabilization systems including boneplates of varying sizes and orientations, intramedullary nails ofvarying sizes and orientations, fasteners including locking fasteners,non-locking, compression fasteners, polyaxial fasteners, fixed anglefasteners, or any other suitable fasteners, drill guides, k-wires,sutures, and other components for installing the same.

BRIEF DESCRIPTION OF THE DRAWING

A more complete understanding of the present invention, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIGS. 1A-1G depict a stabilization system according to one embodimentincluding a proximal humerus plate and a plurality of bone fasteners;

FIGS. 2A-2F depict pre-loaded drill guides suitable for use with thestabilization system described with respect to FIGS. 1A-1G;

FIGS. 3A-3G depict alternative versions of drill guides according toother embodiments;

FIGS. 4A-4H show a stabilization system according to another embodimentincluding a proximal humerus plate and an intramedullary nail securedwith a plurality of bone fasteners;

FIG. 5 is a top perspective view of two fasteners engaged withcombination holes according to an embodiment;

FIG. 6 is a close-up view of an alternative version of a combinationhole according to another embodiment;

FIGS. 7A-7C show a perspective view, top view, and cross-section view,respectively, of an another embodiment of a combination hole;

FIGS. 8A-8C show a perspective view, top view, and cross-section view,respectively, of an another embodiment of a combination hole;

FIGS. 9A-9C show a perspective view, top view, and cross-section view,respectively, of an another embodiment of a hole for receiving afastener;

FIGS. 10A-10C show a perspective view, top view, and cross-section view,respectively, of an another embodiment of a combination hole;

FIGS. 11A-11C show a perspective view, top view, and cross-section view,respectively, of an another embodiment of separate locking andnon-locking holes;

FIGS. 12A-12D show a perspective view, a top view, a cross-section view,and a perspective view with a locking fastener, respectively, accordingto another embodiment of a plate including three overlapping locking andnon-locking holes;

FIGS. 13A-13B show perspective views of a plate according to anotherembodiment with locking and non-locking functionality;

FIGS. 14A-14E shows alternative locking screw and openings in platesaccording to yet another embodiment;

FIGS. 15A and 15B depict a perspective view and cross-section view of analternative version of a plate with blocking screws;

FIGS. 16A and 16B depict a fastener according to another embodiment withself-forming threads configured to form threads in the opening of aplate;

FIGS. 17A and 17B depict an opening in a plate according to oneembodiment having a windswept cut configured to receive the self-formingthreads of the fastener of FIGS. 16A-16B;

FIGS. 18A and 18B depict an opening in a plate according to anotherembodiment having a knurled cut configured to receive the self-formingthreads of the fastener of FIGS. 16A-16B;

FIGS. 19A and 19B depict an opening in a plate according to anotherembodiment having a polygonal cut configured to receive the self-formingthreads of the fastener of FIGS. 16A-16B; and

FIG. 20A depicts an alternative opening in a plate according to anotherembodiment;

FIG. 20B depicts another alternative opening in a plate according to yetanother embodiment; and

FIGS. 21A-21D depict a plate assembly according to one embodiment wherea locking or non-locking fastener may be positioned at an angle orperpendicular to the plate.

DETAILED DESCRIPTION

Embodiments of the disclosure are generally directed to devices,systems, and methods for bone stabilization, especially proximal humeralstabilization. Specifically, embodiments are directed to proximalhumerus stabilization systems including a bone plate configured to siton a lateral surface of the proximal humerus and supporting thefractured head of the humerus. Other embodiments are directed towarddrill guides configured to guide predrilling of pilot holes forinsertion into the bone plate. Further embodiments are directionalternative proximal humerus stabilization systems including a boneplate used in conjunction with an intramedullary nail. The fasteners maybe configured to secure both the bone plate and the intramedullary nail.Still other embodiments are directed to different types of holes andfasteners configured to provide locking and/or compression to the bone.

The bone plate and/or intramedullary nail may be comprised of titanium,stainless steel, cobalt chrome, carbon composite, plastic orpolymer—such as polyetheretherketone (PEEK), polyethylene, ultra highmolecular weight polyethylene (UHMWPE), resorbable polylactic acid(PLA), polyglycolic acid (PGA), combinations or alloys of such materialsor any other appropriate material that has sufficient strength to besecured to and hold bone, while also having sufficient biocompatibilityto be implanted into a body. Similarly, the fasteners may be comprisedof titanium, cobalt chrome, cobalt-chrome-molybdenum, stainless steel,tungsten carbide, combinations or alloys of such materials or otherappropriate biocompatible materials. Although the above list ofmaterials includes many typical materials out of which bone plates,intramedullary nails, and bone fasteners are made, it should beunderstood that the bone plates, intramedullary nails, and fastenerscomprised of any appropriate material are contemplated.

The embodiments of the disclosure and the various features andadvantageous details thereof are explained more fully with reference tothe non-limiting embodiments and examples that are described and/orillustrated in the accompanying drawings and detailed in the followingdescription. The features of one embodiment may be employed with otherembodiments as the skilled artisan would recognize, even if notexplicitly stated herein. Descriptions of well-known components andprocessing techniques may be omitted so as to not unnecessarily obscurethe embodiments of the disclosure. The examples used herein are intendedmerely to facilitate an understanding of ways in which the disclosuremay be practiced and to further enable those of skill in the art topractice the embodiments of the disclosure. Accordingly, the examplesand embodiments herein should not be construed as limiting the scope ofthe disclosure, which is defined solely by the appended claims andapplicable law. Moreover, it is noted that like reference numeralsrepresent similar features and structures throughout the several viewsof the drawings.

Proximal Humeral Plate System

Referring now to the drawing, FIGS. 1A-1G depict an embodiment of aproximal humerus stabilization system 100 including a bone plate 110configured to sit on a lateral surface of the proximal humerus 102 andsupporting the fractured head 104 of the humerus 102 and one or morebone fasteners 130 configured to be received in the bone plate 110 andsecured to the humerus 102. The humerus 102 is a long bone in the arm orforelimb that runs from the shoulder to the elbow. Although generallydescribed with reference to the humerus 102, it will be appreciated thatthe stabilization systems described herein may be used or adapted to beused for the fixation of other long bones as well, such as the femur,radius, tibia, etc.

The bone plate 110 extends from a first end 112 configured to bepositioned proximate to a distal portion of femur 102 to a second end114 configured to be positioned proximate to the head 104 of the femur102. The plate 110 includes a top surface 116 and an opposite, bottomsurface 118 configured to contact adjacent bone. The top and bottomsurfaces 116, 118 are connected by opposite side surfaces extending fromthe first to second ends 112, 114 of the plate 110. With emphasis onFIGS. 1F-1G, the bottom surface 118 of the plate 110 includes ananatomic contour configured to follow the best approximation of averageproximal humerus anatomy, wrapping posteriorly towards the proximalportion of the plate 110, thereby buttressing the greater tuberosity.The plate 110 is designed to sit low avoiding acromial impingement. Theplate 110 further has a low profile proximal portion. The plate 110tapers towards the proximal portion of the plate 110 with a very thincross section to avoid impingement. The plate 110 gets thicker distallyto support load across fracture site. In longer plates 110 (e.g., 135 mmand longer), the plate 110 may have a thicker cross section distally toallow surgeons to adequately stabilize multiple fractures or a longspiral proximal humerus fracture that translates down the shaft of thehumerus 102. This consideration may be especially important when fixinga fracture using the bridging technique (e.g., bridging a fracture) whenplate stress may be higher.

The bone plate 110 includes an elongated portion 140 extending along alongitudinal axis L having a length greater than its width. Theelongated portion 140 is configured to contact the shaft of the femur102. The elongated portion 140 may terminate at the first end 112 with ataper such that it has a width and/or thickness less than the remainderof the elongated portion 140. The bone plate 110 also includes anenlarged head portion 142 extending from the elongated portion 140. Theenlarged head portion 142 or a portion thereof is configured to contactthe head 104 of the femur 102. The enlarged head portion 142 has a widthgreater than the width of the elongated portion 140. The enlarged headportion 142 extends along an axis A at an angle relative to thelongitudinal axis L of the elongated portion 140. The angle of the headportion 142 relative to the elongated portion 140 may range from about10-60°, about 20-50°, about 30-40°, about 40-50°, or another appropriateangle. As best seen in FIG. 1D, the bone plates 110 may be available ina variety of lengths based on the anatomy of the patient. The plates 110are configured to sit on the lateral surface of the proximal humerus 102and supporting the head 104 of the humerus 102. The plates 110 areconfigured in both left and right designs, in a mirrored configuration,in order to address the anatomy of both the left and right arms of thepatient.

As best seen in FIGS. 1F and 1G, the bottom surface 118 of the plate 110may include a plurality of scallop cuts 119 located along the elongatedportion 140 between the fastener openings 120. The scallop cuts 119 maybe in the form of partially cylindrical valleys cut around a peripheryof the bottom surface 118 of the plate 110. This shields stress from thefastener openings 120 during bending, discouraging hole warping effectswhile recontouring the plate 110. This also reduces contact between theplate 110 and the bone surface, thereby helping to preserve blood supplyto the bone and prevent osteonecrosis. In addition to the scallop cuts119, a plurality of dimples may be positioned along the bottom surface118 of the plate 110 (e.g., along the entire bottom surface 118 or aportion thereof) to further reduce contact between the plate 110 andbone surface, further helping to preserve blood supply and preventosteonecrosis.

The plate 110 includes one or more through openings 120 configured toreceive one or more bone fasteners 130. The openings 120 extend throughthe body of the plate 110 from the top surface 116 to the bottom surface118. The openings 120 may include cylindrical openings, conicalopenings, elongated openings, threaded openings, textured openings,non-threaded and/or non-textured openings, and the like. The openings120 may allow for locking of the fastener 130 to the plate 110 or mayallow for movement and dynamic compression of the bone. The plate 110may comprise any suitable number of openings 120 in any suitableconfiguration. These openings 120 allow surgeons more flexibility forfastener placement, based on preference, anatomy, and fracture location.Surgeons may have differing opinions as to the number, location, andtypes of fasteners 130. Further, complexity of fracture location andshape makes having as many locations for fasteners 130 as possiblenecessary. This design offers surgeons a versatile method to achievehigher accuracy in placement of the fasteners 130.

The openings 120 may be configured to receive one or more bone fasteners130. The fasteners 130 may include locking fasteners, non-lockingfasteners, or any other fasteners known in the art. The fasteners 130may comprise bone screws or the like. The fasteners 130 may also includeother fasteners or anchors configured to be secured or engaged withbone, such as nails, spikes, staples, pegs, barbs, hooks, or the like.The fasteners 130 may include fixed and/or variable angle bone screws.The fastener 130 may include a head portion 132 and a shaft portion 134configured to engage bone. For a locking fastener 130, the shaft portion134 may be threaded such that the fastener 130 may be threaded into thebone. The head portion 132 may include a textured area, such as threads,around its outer surface sized and configured to engage with the opening120, for example, and corresponding threads in the opening 120 in orderto lock the fastener 130 to the plate 110. In the alternative, for anon-locking fastener 130, the head portion 132 may be substantiallysmooth to allow for dynamic compression of the bone.

As best seen in FIGS. 1B and 1C, the openings 120 include two holes 120Apresent in the midsection of the plate 110 that are nominally aimedtoward the calcar region 106 of the proximal humerus 102, which mayconstitute the best quality bone in the region. The holes 120A may bepolyaxial openings configured to accept fasteners 130A that can be aimedat the calcar region 106 for best bone purchase. The fasteners 130A maybe aimed, for example, within a 40° cone at the calcar region 106. Anupper portion of the hole 120A may be tapered 128 and a portion of theplate 110 around the hole 120A may be enlarged or increased in thicknessto allow for the proper angle of the fasteners 130A to be achieved.

These fasteners 130A may be in the form of polyaxial calcar bone screws.The calcar fasteners 130A may be generally larger (e.g., in lengthand/or diameter) than the other fasteners securing the plate 110 to thebone. The fasteners 130A are optionally cannulated to allow for preciseplacement with a k-wire (not shown) if desired by the surgeon. Anotheradvantage of the polyaxial calcar fastener 130A is that the plate 110can be placed in a wide range of locations in the proximal/distaldirection, allowing the surgeons to avoid impingement, especially insmall bones, and still achieve excellent purchase in the calcar 106because of the polyaxiality of the fastener 130A. The calcar fasteners130A may include polyaxial screws having self-forming threads that workby displacement of the plate material, which are described in moredetail herein. The plate 110 may further include an opening 120configured to receive a fixed angle calcar fastener 130B. The fixedangle calcar fastener 130B may be positioned in the mid-section of theplate 110 if the surgeon would like to use the fixed angle fastener 130Bto line up the plate 110 relative to the bone.

Turning now to FIG. 1E, the openings 120 further include a plurality ofholes 120B present in the head portion 142 of the plate 110. These holes120B may be nominally aimed toward the head 104 of the humerus 102. Theholes 120B may be fixed openings configured to accept fixed anglefasteners 130B that can be secured into the head 104 of humerus 102. Thefasteners 130B may have predetermined trajectories based on theorientations of the openings 120B. An upper portion of the holes 120Bmay be tapered 128 to allow for the proper positioning of each of thefasteners 130B. Each of the fasteners 130B may be angled along adifferent trajectory than the other respective fasteners 130B. Some ofthe fasteners 130B may have a greater angulation than other respectivefasteners 130B. As shown, the holes 120B receive nine fixed anglefasteners 130B in the humeral head 104 having predefined trajectoriesforming divergent and convergent patterns. The convergent patterns actas a buttress in supporting the low density bone in the center of thehead 104. The divergent screws reach out to the anterior, posterior andsuperior portions of the humeral head 104. The screw holes 120B andscrew heads 132 may have mating conical threads that lock the screw 130Bin both angular and axial alignment to prevent collapse and backout.

With emphasis on FIGS. 1C and 1F, the openings also include one or moreholes 120C present along the elongated portion 140 of the plate 110 andconfigured to accommodate a compression fastener 130C. The hole or holes120C may be elongated along the longitudinal axis L of the elongatedportion 140. The holes 120C may include ramped surfaces on the ends topermit dynamic compression plating. The elongated hole(s) 120C aresituated in the distal portion of the plate 110. The elongated holes120C may have varying lengths. As seen in FIG. 1D, additionalcompression holes 120C may be provided for the longer plate constructs.The holes 120C are configured to accommodate non-locking, compressionscrews 130C the heads of which have a spherical underside so the screw130C may be placed at varying angles. The compression screw 130C can beinserted and preliminarily tightened to secure the plate 110 to thebone. As the screw 130C is inserted eccentrically in to the hole 120C,the screw 130C slides down the slot 120C, displacing the plate 110 andthe bone as well. The compression screw 130C may have a shorter lengthand/or a smaller diameter than the proximal head screws 130B. If theplate 110 needs to be adjusted later, the screw 130C can be loosened andthe plate 110 can be shifted in the proximal and/or distal directions.This slot 120C also accommodates reduction of the humeral shaft byinserting a very long compression screw 130C and pulling the bone to theplate 110.

As best seen in FIG. 1E, the head portion 142 of the plate 110 may alsocomprise a plurality of openings 122 configured as suture holes toreceive sutures to secure the plate 110 to surrounding tissue. Thesuture openings 122 may include a plurality of generallytriangular-shaped holes situated around the perimeter of the proximalsection of the plate 110. The suture openings 122 may be amply sized tofit commonly used sutures and needles. The openings 122 may haveundercuts (e.g., recesses on the bottom surface 118) to fit the sutureeven when the plate 110 is fully compressed to the bone. The openings122 may also have generous rounds, as to not cut through suture wirewhile in use.

The plate 110 may further comprise a plurality of openings 124configured to receive one or more k-wires (not shown). The k-wire holes124 may comprise small diameter holes (e.g., having a diametersignificantly smaller than the fastener openings 120). The k-wire holes124 may be located in both proximal and distal sections of the plate 110to allow preliminary placement of the plate 110 against the bone and/orto aid in reduction of the fracture. Distal k-wire holes 124 follow theanterior side of the plate 110 to make k-wire placement easier in theanterolateral approach.

The bone plate 110 may be attached to a proximal humerus to fixate oneor more bone fractures or fragments and thereby promote healing of thebone. The plate 110 further restores the anatomic alignment of theproximal humerus 102. The plate 110 may be positioned against thelateral surface of the humerus 102. One or more k-wires may be suppliedthrough the k-wire holes 124 to assist with preliminary placement of theplate 110. One or more sutures may be tied through the suture holes 122to secure the plate 110 to the tissue before or after the fasteners 130are inserted. Pilot holes may be drilled through the fastener openings120 to prepare to receive the respective fasteners 130. The fasteners130A, 130B, 130C may be positioned through the respective openings 120A,120B, 120C and into the humerus 102. The fasteners 130 may be affixed tothe bone in any suitable order, number, and orientation depending on theanatomy of the bone and the fracture.

Drill Guides

In some embodiments, it may be desirable to drill pilot holes beforeinsertion of the fasteners 130. FIGS. 2A-2F depict one embodiment ofdrill guides 160 that may be suitable for use with the bone plate 110.Drill guides 160 allow a drill 170 to create a hole at the trajectorythat the fastener 130 is intended to be inserted, guaranteeing that thepilot hole will be aligned with how the fastener 130 is designed to beinserted into the plate 110. According to one embodiment, the plates 110may have drill guides 160 pre-installed into the plate 110 by themanufacturer. The pre-installed drill guides 160 may save the surgeontime in switching between instruments to drill pilot holes in theoperating room. In the alternative, the drill guides 160 may be attachedto the plate 110 at any suitable time before or during the operation.

The bone plates 110 may be designed to accommodate locking fasteners 130which anchor into bone and lock to the plate 110 creating a fixedconstruct. Depending on the opening 120 in the plate 110, the fasteners130 may be intended to have one fixed, nominal trajectory in which theycan be inserted into the plate 110 for proper locking to occur. Atapered external thread on the head portion 132 of the fastener 130 isconfigured to interface with an internal tapered thread in the opening120 of the plate 110, thereby locking the fastener 130 to the plate 110.

Instead of traditional single drill guides, which require the guide tobe positioned over each respective opening 120, each plate 110 may havedrill guides 160 already inserted into therein at each respectivelocking hole 120. The surgeon would then be able to immediately drillthe pilot hole, for example, with the drill 170, through thepre-installed drill guide 160 without having the extra step of loading atraditional drill guide for each fastener 130 to be inserted. After thefastener 130 is inserted, the screw guide 160 may be removed, forexample, with a self-retaining hexalobular or hexagonal female recess162 on the top of the drill guide 160.

The pilot holes may be drilled after the plates 110 are provisionallyplaced, and before insertion of bone fasteners 130 into the bone. Manylocking holes 120 have trajectories that are not oriented normal to thetop surface 116 of the plate 110, and therefore can be difficult tothread in without knowing the nominal trajectory. Accordingly, the screwguides 160 will further provide an easy way to achieve the desiredtrajectory, and the pilot hole(s) can define the trajectory that thefastener 130 will follow during insertion. In order for the construct tolock properly, the trajectory of the fastener 130 should be correct sothat the complimentary tapered threads of the fastener 130 and theopening 120 are able to interface.

The pre-installed drill guide 160 may extend from a first end to asecond end configured to be received in one of the openings 120 in theplate 110. To engage the plate 110, the second end of the drill guide160 may include a plurality of external threads 164 configured to engagecorresponding threads in the opening 120. The external thread 164 mayextend along a portion of the length of the drill guide 160 (e.g., lessthan half or less than a third of the length) or along the entire lengthof the drill guide 160. The drill guide 160 may have a head similar tothe head portion 132 of the locking bone fastener 130, for example, onthe bottom, with a round section protruding from the top of the plate110. The center of the guide 160 may include a hole or cannulatedopening 166 extending through its entirety with a diameter slightlylarger than the drill 170 to allow for a slip fit. The first end of thedrill guide 160 may include the female recess 162, such as but notlimited to hexalobe or hexagon, and being larger than the cannulatedhole 166 for guide removal. The female recess 162 for removal may beself-retaining so that the drill guide 160 can be removed and stay inplace on the driver for removal from body. In an alternative embodiment,the outside of the drill guide 160 is shaped as a male feature, such asa hexagon, for removal with the use of a socket-like driver or the like.

FIG. 3A depicts an alternative version of a drill guide or backpack 160Athat can be attached to the proximal portion 142 of the plate 110. Thedrill guide or backpack 160A may include a plurality of cannulatedopenings 166A which correspond to each of the respective fixed angleopenings 120 in the plate 110. The drill guide openings 166A may beconfigured in order to drill the pilot holes at the appropriatetrajectories for each opening 120, and subsequently receive therespective fasteners 130 at the correct trajectories. The drill guide160A may also include a plurality of k-wire openings which match withthe k-wire openings 124 in the plate 110.

The drill guide or backpack 160A may be secured to the plate 110 withone or more fasteners 168. The fastener 168 may be threaded into theplate 110 or may be otherwise configured to temporarily secure the drillguide 160A to the plate 110. The drill guide 160A may be pre-assembledto the plate 110 or may be attached at any other suitable time before orduring the surgery. The fastener 168 may be secured, for example, in theoperating room, via thumb or hexalobular fastener, to attach the drillguide 160A to the plate 110.

In the embodiment shown in FIG. 3B, the fastener 168 may be in the formof a screw 168, for example, having an enlarged head portion 169 with arecess for receiving a driving instrument and a threaded shaft portionextending from the head portion 169. The screw 168 may be in the form ofa single lead screw or may be otherwise suitably configured to attachthe drill guide 160A to the plate 110. FIG. 3B shows the underside ofthe backpack 160A with a distal end of the screw 168 protrudingtherefrom and a close-up view of the screw 168. The underside of thebackpack 160A may be contoured to the top side of the proximal humerusplate 110, but may only contact at one or more protrusions 163 (e.g.,three small protrusions 163 or “bosses”) to guarantee that the backpack160A is positioned correctly regardless of plate contour variations.

As best seen in FIG. 3C, the proximal portion 142 of the plate 110 mayinclude an opening 126 configured to accept a portion of the screw 168.The opening 126 may include a flange 127 extending partially orcompletely around the perimeter of the opening 126. In order to form theflange 127, the opening 126 may be counterbored from the top and bottomso that only the flange 127 is left. In other words, the flange 127 maybe recessed into the opening 126 from the top and bottom surfaces 116,118 of the plate 110. The remaining flange 127 may have top and bottomsurfaces that are normal to the axis of the opening 126. When a partialflange is desired, material may be removed so that a partial flange 127remains. In the embodiment shown, the flange 127 occupies 180 degrees ofthe opening 126. Other designs may include more or less flange 127occupying the opening 126.

By way of example, once the backpack 160A is positioned adjacent theplate 100, the thread in the single pitch screw 168 can start in thebackpack 160A and compress the backpack 160A to the plate 110. Thebackpack 160A may have an accompanying drill guide that freely fits intoholes in the backpack 160A to drill the screw hole at the correcttrajectory. After the pilot holes are drilled, the drill guide may thenbe removed and the fasteners 130 positioned through the respectiveopenings 120. The screws can fit through the backpack 160A and are alsoguided at the correct trajectory. The backpack 160A may be relativelyslim in thickness, for example, not protruding more than 10 mm above theplate 110, to allow for manipulation of the humerus 102 while notimpinging on soft tissue.

FIGS. 3D-3G illustrate yet another version of a drill guide 161 that canbe attached to the proximal portion of the plate 110. The drill guide161 may include a plurality of cannulated openings 167 which correspondto each of the respective fixed angle openings 120 in the plate 110. Thedrill guide openings 167 may be configured in order to drill the pilotholes at the appropriate trajectories for each opening 120, andsubsequently receive the respective fasteners 130 at the correcttrajectories. The drill guide 161 may also include a plurality of k-wireopenings which match with the k-wire openings 124 in the plate 110.After the pilot holes are drilled, the drill guide 160A may then beremoved and the fasteners 130 positioned through the respective openings120. The drill guide 161 may be relatively slim in thickness, forexample, not protruding more than 10 mm above the plate 110, to allowfor manipulation of the humerus 102 while not impinging on soft tissue.

As seen more clearly in FIGS. 3E-3F, the drill guide 161 can be attachedto the plate 110 via a deformable stud with round protrusions 163 thatinterface with a hole provided with an undercut. In a preferredembodiment, the drill guide 161 is provided with at least threeprotrusions 163 that interface with a corresponding hole on the plate110 for attachment purposes. In one embodiment, one of the protrusions163 is deformable and is provided with radial extension that interfaceswith the inner surface of the hole to maintain a secure attachment withthe plate 110, as illustrated in FIG. 3F. In another embodiment, thedrill guide 161 may be provided with greater than three projections tosecure the drill guide 161 to the plate 110.

The drill guide 161 may be configured to couple with a supplementaldrill guide that freely fits into holes in the drill guide 161 to drillthe screw hole at the correct trajectory. The supplemental drill guideis then removed and screw can fit through the drill guide 161 and areguided at the trajectory directed by the guide. The underside of thedrill guide 161 will be contoured to the top side of the proximalhumerus plate, but only interface with the plate at the threeprotrusions so that the guide 161 may be positioned correctly regardlessof plate contour variations. In one exemplary embodiment, at least oneof the plurality of protrusions may be provided with a ledge 165 thatcontacts the surface of the plate 110. In another embodiment, theunderside surface of the drill guide 161 contacts the entire surface ofthe plate. In yet another embodiment, the underside drill guide surfacedoes not contact the upper surface of the plate. The drill guide 161 maybe contoured to match the contour of the plate.

The drill guide 161 may be made of plastic or metal. The drill guide 161can be pre-installed and then removed after fasteners are positionedwithin the bone. In another embodiment, located on the bottom surface ofthe plate, there are dimples which reduce contact between the plate andthe bone surface, helping preserve blood supply to the bone and preventosteonecrosis.

Proximal Humeral Plate and Intramedullary Nail System

According to another embodiment exemplified in FIGS. 4A-4F, the proximalhumerus stabilization system 200 may include a bone plate 210 configuredto sit on a lateral surface of the proximal humerus 102 and supportingthe fractured head 104 of the humerus 102, an intramedullary nail 250configured to be positioned inside the intramedullary canal of thehumerus 102, and one or more bone fasteners 230 configured to bereceived through the bone plate 110 and the intramedullary nail 250 andsecured to the humerus 102.

The bone plate 210 may include similar features as the standalone boneplate 110 described above. As best seen in FIG. 4B, the bone plate 210extends from first end 212 to second end 214 and includes top surface216 and opposite, bottom surface 218 configured to contact adjacentbone. The bone plate 210 includes elongated portion 240 extending alonglongitudinal axis L having a length greater than its width and includingenlarged head portion 242 extending from the elongated portion 240. Theenlarged head portion 242 may extend along axis A at an angle relativeto the longitudinal axis L of the elongated portion 240.

Similar to plate 110, plate 210 includes one or more through openings220 configured to receive one or more bone fasteners 230. The openings220 may include cylindrical openings, conical openings, elongatedopenings, threaded openings, textured openings, non-threaded and/ornon-textured openings, and the like. The fasteners 230 may includelocking fasteners, non-locking fasteners, or any other fasteners knownin the art. The openings 220 may allow for locking of the fastener 230to the plate 210 or may allow for movement and dynamic compression ofthe bone. The plate 210 may comprise any suitable number of openings 220in any suitable configuration.

The fasteners 230 may include fixed and/or variable angle bone screws.The fastener 230 may include head portion 232 and shaft portion 234configured to engage bone. The shaft portion 234 may be threaded suchthat the fastener 230 may be threaded into the bone. For a lockingfastener 230, the head portion 232 may include a textured area, such asthreads, around its outer surface sized and configured to engage withthe opening 220, for example, and corresponding threads in the opening220 in order to lock the fastener 230 to the plate 210. In thealternative, for a non-locking fastener 230, the head portion 232 may besubstantially smooth to allow for dynamic compression of the bone.

As best seen in FIG. 4B, similar to plate 110, the plate 210 includestwo holes 220A present in the midsection of the plate 210 that arenominally aimed toward the calcar region 106 of the proximal humerus102. The holes 220A may be polyaxial openings configured to acceptpolyaxial calcar fasteners 230A that can be aimed at the calcar region106 for best bone purchase. A portion of the hole 220A (e.g., around theperimeter on the top surface 216) may be tapered 228 to allow for thetrajectory of the fasteners 230A to reach the calcar region 106. Theplate 210 may further include an opening 220B configured to receive afixed angle calcar fastener 230B. The plate 210 may further include aplurality of fixed angle holes 220B present in the head portion 242 ofthe plate 210, which are nominally aimed toward the head 104 of thehumerus 102. The fixed angle fasteners fasteners 230B may havepredetermined trajectories based on the orientations of the openings220B. As shown, the holes 220B receive seven fixed angle fasteners 230B.The plate 210 may also include one or more elongated holes 220C presentalong the elongated portion 240 of the plate 210 and configured toaccommodate a compression and/or locking fastener 230C. The head portion242 of the plate 210 may also comprise a plurality of suture holes oropenings 222 configured to receive sutures and secure the plate 210 tosurrounding tissue, and a plurality of k-wire holes or openings 224configured to receive one or more k-wires (not shown).

Turning now to FIGS. 4A and 4C, the proximal humerus stabilizationsystem 200 may further include intramedullary nail 250 configured to bepositioned inside the intramedullary canal of the humerus 102. It willbe appreciated that the plate 210 and/or the intramedullary nail 250 mayeach be used alone or may be used together in combination for humeralstabilization.

The intramedullary nail 250 includes an upper portion 252 and a lowerportion 254. The upper portion 252 being proximal to or configured to bepositioned substantially within the humeral head 104 and the lowerportion 254 being distal to the humeral head 104 and configured toextend substantially into the shaft of the humerus 102. The upper andlower portions 252, 254 may each have a width (or diameter) and alength. The width or diameter of the upper portion 252 may be greaterthan the width or diameter of the lower portion 254, and the length ofthe lower portion 254 may be greater than the length of the upperportion 252. Preferably, the upper portion 252 is sized and dimensionedto be substantially received within the humeral head 104 and the lowerportion 254 is sized and dimensioned to be substantially received withinthe intramedullary canal.

In one embodiment, the upper portion 252 is configured as a cage,cylinder, or tube. It should be noted that the upper portion 252 may beany geometrical shape that best suits the positioning of the implant 250within the humeral head 104. For instance, the upper portion 252 may berectangular, oblong, polygonal, or the like. The upper portion 254 ofthe implant 250 may form a unitary body having a plurality of throughopenings or holes 256 for receiving the fasteners 230 described herein.The holes 256 may be positioned on the upper portion 252 so that thefasteners 230 enter the holes and rigidly couple the upper portion 252to bone and/or bone fragments of the humeral head 102. Each of theplurality of holes 256 of the upper portion 252 may have an entry pointand an exit point. The holes 256 may be threaded or textured (e.g., toreceive locking fasteners 230) or non-threaded/non-textured (e.g., toreceive compression fasteners 230).

In another embodiment, the upper portion 252 may be configured having ahollow body with the plurality of holes 256 on the exterior surface ofthe cylinder and extending through the width or diameter of thecylinder. In another embodiment, the upper portion 252 may be configuredas an expandable device, so that it enters the humeral head 104 in afirst, collapsed configuration and then is expanded into a second,expanded configuration. In yet another embodiment, shown in FIGS. 4G and4H, the upper portion 252 may be comprised of mesh or have a mesh-likesurface. The cage or upper portion 252 may have a coarser mesh than thediameter of the fasteners 130 to allow screws to be passed through themesh to lock the cage in place or the screws may be the same size orsmaller and the cage may be able to deform. The mesh may besubstantially rigid or may have some flexibility.

The lower portion 254 may be configured as an elongate shaft or stem.The lower portion 254 of the implant 250 may be a single body thatextends from the upper portion 252 towards the distal portion of thehumerus 102. The lower portion 254 may be configured as a cylindricalshaft, however, the shaft may be configured as any geometrical shape(e.g., rectangular, oblong, polygonal, or the like) that suits theintramedullary canal. The shaft or lower portion 254 may be compatiblewith reverse or hemi shoulder arthroplasty implants.

The lower portion 254 may form a unitary body having a plurality ofthrough openings or holes 256 for receiving fasteners 230 as describedherein. Each of the plurality of holes 256 of the lower portion 254 mayhave an entry point and an exit point. The holes 256 may be threaded ortextured (e.g., to receive locking fasteners 230) ornon-threaded/non-textured (e.g., to receive compression fasteners 230).The holes 256 in the lower portion 254 may be conical, for example, toaccept polyaxial screws in the plate 210. In another embodiment, thelower portion 254 may be configured having a hollow body with theplurality of holes 256 on the exterior surface of the shaft andextending through the width or diameter of the shaft. For the lockingfasteners 230, the screw heads may have optional thread in sutureanchors to capture rotator cuff tendons. The lower portion 254 may havean optional hydroxyapatite (HA) coating, smooth or porous coatings.According to another embodiment, the lower portion 254 may be configuredto have mesh type surface, similar or different from the mesh of theupper portion 252. According to yet another embodiment, the lowerportion 254 may also be made with an expandable diameter to givesurgeons greater flexibility in sizing and also facilitate distallocking, reducing typical complications.

In one embodiment, the upper portion 252 and the lower portion 254 areconfigured as a single, unitary body. The intramedullary implant 250 maybe anatomically shaped, for example, with a range of medial bendstowards the proximal head for increased support. In an alternativeembodiment, shown in FIG. 4D, the upper and lower portions 252, 254 maybe comprised of two separate components that may be coupled to oneanother, for example, through a mechanical mechanism. As shown, thelower portion 254 may include a male, threaded portion and the upperportion 252 may include a female, threaded portion (not visible)configured to receive the male, threaded portion of the lower portion254 to couple the two parts together. The upper and lower portions 252,254 may be coupled together by any suitable means, such as a dovetailconnection, press-fit, threaded, snap-fit, or the like. In otherembodiments, it should be noted that the upper portion 252 and the lowerportion 254 can be exchanged and/or interchangeable to facilitatefixation of different fractures and anatomies.

According to one embodiment, the bone plate 210 may be attached to thelateral aspect of the proximal humerus 102 to fixate one or more bonefractures or fragments. The intramedullary nail 250 may be inserted intothe intramedullary canal. Before or after insertion, bone graft materialcan be inserted or injected into the upper and/or lower portions 252,254 of the nail 250 if desired. In addition, the distal end of the lowerportion 254 may also be cemented or press fit in to the canal based onsurgeon preference. One or more k-wires may be supplied through thek-wire holes 224 to assist with preliminary placement of the plate 210and/or intramedullary nail 250. One or more sutures may be tied throughthe suture holes 222 to secure the plate 210 to the tissue before orafter the fasteners 230 are inserted.

Pilot holes may be drilled through the fastener openings 220 to prepareto receive the respective fasteners 230. One or more drill guides may beattached to the humeral implant 250 before or during surgery to aid ininsertion of lower portion 254 and/or nail 250 into the shaft of thehumerus 102. The guide may be used to aim the drill for two distal screwholes. The distal screws 230 may be inserted and then the guide may berigidly attached to the distal screws 230. The aiming arm may bedisconnected from the proximal end of the nail 250. The proximal bonefragment may be placed on top of the nail 250 and the guide may be usedto drill screw holes into the proximal nail 250. The screw length andsize may be determined so that the articular surface is not affected.The guide may also adapt to connect to lateral platting to synchronizethe hole positions.

The fasteners 230A, 230B, 230C may be positioned through the respectiveopenings 220A, 220B, 220C in the plate 210, through the respectivethrough holes 256 in the upper and lower portions 252, 254 of the nail250, and into the humerus 102. The fasteners 230 may be affixed to thebone in any suitable order, number, and orientation depending on theanatomy of the bone and the fracture. In operation, each of theplurality of holes 220 of the plate 210 are positioned so that the holes220 are geometrically are aligned with the plurality of holes 256 of theupper portion 252 and the lower portion 254 of the intramedullaryimplant 250. In another embodiment, the upper and lower portions 252,254 may be designed with a degree of eccentricity so that during theimplantation procedure, when the end of the lower portion 254 is rotatedin the intramedullary canal, the upper portion 252 having a largerdiameter, may act as a cam pushing the humeral head 104 medially intoposition. The plate 210 and/or intramedullary nail 250 is configured torestore the anatomic alignment and stabilize the proximal humerus 102.It is contemplated that the plate 210 may be used alone in thestabilization, the nail 250 may be used alone in the stabilization, orboth the plate 210 a nail 250 may be used together in the stabilization.

The stabilization system 200 may provide the benefit of medial supportto prevent collapse, ability to manipulate fragments using the device,and minimize the need for allograft, thereby decreasing biocompatibilityissues. Other benefits may include minimizing the time spent shaping thefibula in the operating room, using a drill guide as a positioning armfor nail placement, and reducing negative affects to the rotator cuff.The system 200 also provides the benefit of either using or not usingthe lateral plate 210. When not using the lateral plate 210, the nail250 allows for a less invasive surgical approach, helps to avoidimpingement, and may increase patient comfort.

Alternative Hole Configurations

The fixed and variable angle, locking and non-locking openings 120, 220(e.g., including openings 120A, 120B, 120C, 220A, 220B, 220C) andrespective fasteners 130, 230 (e.g., including 130A, 130B, 130C, 230A,230B, 230C) described herein may be substituted with or include one ormore of the following openings 20 and/or fasteners 30, 40. The openings20 and/or fasteners 30, 40 are generally described with reference to ageneric plate 10, which may include plate 110, 210, or any othersuitable plate design.

Referring now to the drawing, FIGS. 5-21 depict alternative openings 20in plate 10. The openings 20 extending through the plate 10 areconfigured to accept locking fasteners 30, non-locking fasteners 40, ora combination of both locking and non-locking fasteners 30, 40 that areable to dynamically compress the bone and/or affix the plate 10 to thebone. When plating diaphyseal bone, surgeons may use a combination ofboth locking and non-locking fasteners 30, 40 that are able todynamically compress bone and to connect the bone and the plate 10.Dynamic compression may also be desirable to create interfragmentalcompression while tightening the fasteners 30, 40.

The plate 10 includes a top surface 16 and an opposite, bottom surface18 configured to contact adjacent bone. The plate 10 includes one ormore through openings 20 configured to receive one or more bonefasteners 30, 40. The openings 20 extend through the body of the plate10 from the top surface 16 to the bottom surface 18. In the embodimentsdepicted in FIGS. 5-6, for example, the openings 20 may be in the formof a combination opening that has at least two overlapping holes. Asshown in FIG. 5, the combination opening 20 includes a first hole 22overlapping a second hole 24. One of the holes 22 may be configured tobe the locking hole 22, thereby able to receive and secure the lockingfastener 30 to the plate 10, and the other of the holes 24 may beconfigured to be the dynamic compression hole 24, thereby allowing thenon-locking fastener 40 to freely move in the hole 24 and apply dynamiccompression. The locking hole 22 may have one or more locking featuresdesigned to engage with a locking fastener 30, and the dynamiccompression hole 24 may be elongated, for example, along the centrallongitudinal axis of the plate 10. The screw holes 22, 24 are notconstrained to parallel axes. This hole geometry may be used in boneplates 10 to utilize either fixed angle or variable angle locking screws30 and/or polyaxial non-locking screws 40 that can achieve dynamiccompression.

These openings 20 allow surgeons more flexibility for fastenerplacement, based on preference, anatomy, and fracture location. Surgeonsmay have differing opinions as to whether non-locking or locking screws30, 40 (or some combination of the two) should be used in diaphysealbone. Further, complexity of fracture location and shape makes having asmany locations for fasteners 30, 40 as possible necessary. This designoffers surgeons a versatile method to achieve higher accuracy inplacement of locking and/or non-locking screws 30, 40.

As best seen in FIG. 5, the locking and non-locking fasteners 30, 40 areshown. The locking and non-locking fasteners 30, 40 may includetraditional fasteners known in the art. The locking and non-lockingfasteners 30, 40 may comprise bone screws or the like. The fasteners 30,40 may also include other fasteners or anchors configured to be securedor engaged with bone, such as nails, spikes, staples, pegs, barbs,hooks, or the like. The fasteners 30, 40 may include fixed and/orvariable angle bone screws.

The locking fastener 30 may include a head portion 32 and a shaftportion 34 configured to engage bone. The shaft portion 34 may bethreaded such that the fastener 30 may be threaded into the bone. Thehead portion 32 of the locking fastener 30 includes a textured area 36around its outer surface sized and configured to engage with the lockinghole 22 of the combination opening 20. The textured area 36 may includethreads, ridges, bumps, dimples, serrations, or other types of texturedareas. As shown, the texture area 36 preferably includes a threadedportion extending substantially from the top of the head portion 32 tothe bottom of the head portion 32 proximate to the shaft portion 34.Thus, when the textured area 36 engages the locking hole 22, the lockingfastener 30 is thereby locked to the plate 10.

The non-locking fastener 40 includes a head portion 42 and a shaftportion 44 configured to engage bone. The shaft portion 44 may bethreaded such that the fastener 40 may be threaded into the bone. Thehead portion 42 of the non-locking fastener 40 is substantially smootharound its outer surface such that is able to slide along the elongatedcompression hole 24. Thus, the non-locking fastener 30 may be coupled tothe plate 10, but not locked thereto to enable dynamic compression ofthe bone. It will be recognized that the head portions 32, 42 of thefasteners 30, 40 may include a recess configured to receive a driver orthe like.

The locking hole portion 22 of the combination opening 20 includes atextured portion 26. The textured portion 26 may include threads,ridges, bumps, dimples, serrations, knurls, or other types of texturedareas. The textured portion 26 may be of the same type (e.g., matingsurfaces) or different from the textured area 36 of the locking fastener30. As shown, the textured portion 26 is serrated or knurled along aninner portion of the hole 22. The knurled surface may include straight,angled, or crossed lines cut or rolled into the material. In theembodiment shown in FIG. 5, the textured portion 26 extends alongsubstantially the entire inner surface of the hole 22. With reference tothe embodiment shown in FIG. 6, the combination hole 20 is substantiallythe same as that shown in FIGS. 5 except that the textured portion 26the locking hole 22 now includes a thin centralized textured ribbon ofmaterial. For example, the textured portion 26 takes up about half orless of the surface area of the hole 22. In this instance, only aportion of the textured area 36 of the head portion 32 of the lockingfastener 30 engages with and locks to the textured portion 26 of thehole 22.

An upper portion of the hole 22 may be tapered 28, without texturing,for example, to facilitate alignment of the fastener 30 with the opening20. As shown in FIG. 7, this tapered portion 28 is enlarged in arearelative to the embodiment in FIG. 5. The hole 22 may be configured toreceive a fixed or variable angle fastener 30. The hole 22 may begenerally conical in shape such that it is wider near the top surface 16of the plate 10 and narrower toward the bottom surface 18 of the plate10. The tapered portion 28 and/or the textured area 26 may be conical inshape. In this embodiment, the locking hole 22 is a textured fixed angleconical hole configured to receive locking fastener 30. The texturedholes 22 may deform as the fastener head 32 interferes with the texturedportion 26 of the hole 22, thereby providing a positive lock between thefastener 30 and the plate 10.

The second hole portion 24 of the combination opening 20 may be anelongated dynamic compression hole. The dynamic compression hole 24 maybe elongated such that it has a length greater than its width. The hole24 may be elongated along the longitudinal axis of the plate 10. In thealternative, the hole 24 may be generally cylindrical such that the hole24 only permits polyaxial movement of the fastener 40. The inner surfaceof the hole 24 may be substantially smooth such that the non-lockingfastener 40 is able to freely pivot and/or slide along the hole 24. Thisprovides for at least two directions of compressive force (e.g., alongthe longitudinal axis and perpendicular to the longitudinal axis of theplate 10). The head portion 42 of the non-locking fastener 40 may besubstantially smooth around its outer surface. The head portion 42 issized and configured to engage with and be retained within the holeportion 24 of the combination opening 20. The hole 24 may be configuredto receive a fixed or variable angle fastener 40. In one embodiment, thehole 24 may be generally conical in shape and/or tapered such that it iswider near the top surface 16 of the plate 10 and narrower toward thebottom surface 18 of the plate 10. In this embodiment, the hole 24 is asmooth variable angle conical hole configured to receive the non-lockingfastener 40. The hole 24 may receive the fastener head 42 allowingmovement of the fastener 40, for example, in a polyaxial fashion and/oralong the length of the hole 22, thereby providing dynamic compressionof the bone.

Turning now to FIGS. 7-13, alternative types of openings 20A-20G, whichprovide for locking and/or non-locking, dynamic compression areprovided. As many of the features of these openings are similar to thecombination openings 20 described already for FIGS. 5-6, only thedifferent features will be further explained.

With reference to FIGS. 7A-7C, the combination opening 20A is similar tocombination opening 20 except that the dynamic compression hole 24A hasthe same general diameter as the locking hole 22A, and the locking hole22A includes a different type of textured portion 26A. In thisembodiment, the locking hole 22A has a first diameter D1, and thedynamic compression hole 24A has a second diameter D2. Unlike theelongated hole 24 described earlier, dynamic compression hole 24A hassubstantially same diameter as the locking hole 22A. Thus, the first andsecond diameters D1, D2 are substantially the same. The hole 24A may beformed by milling or drilling a sphere out of the plate 10 in the centerof the circle with tapers or ramps on either side. The hole 24A is notelongated, but is generally circular and the non-locking fastener 40will be allowed to translate in the hole 24A because the diameter of thehead portion 42 and/or shaft (e.g., bone thread) will be smaller thanthe size of the hole 24A in the plate 10. With respect to hole 22A, thetextured portion 26A of the hole 22A may be in the form of a taperedthread. This tapered thread may generally correspond to a similartapered thread on the locking fastener 30. This hole 22A also does notinclude a tapered portion, and the textured portion 26A begins at theintersection with the top surface 16 of the plate 10. This alternativeopening 20A also provides for the use of both locking and non-lockingfasteners 30, 40 that are able to dynamically compress bone and/or lockthe plate 10 to the bone.

Turning now to FIGS. 8A-8C, the combination opening 20B is similar toother combination openings except that the locking hole 22B includes adifferent type of textured portion 26B. The textured portion 26Bincludes a series of alternating recesses and protrusions around acentral portion of the hole 22B. The recesses may be in form of a waveof alternating cutouts extending around the inner perimeter of the hole22B. The textured portion 26B may lock the fastener 30 with a frictionfit or may be modified during insertion of the fastener 30 to form alock in situ. In this embodiment, the locking hole may allow forpolyaxial locking. The plate 10 and the locking fastener 30 may be madeof dissimilar materials having dissimilar hardness values. For example,the fastener 30 may have a higher hardness (e.g., on the Rockwell scale)relative to the plate 10, which may be formed of a material having alower relative hardness value. Due to the increased hardness, the headportion 32 of the locking fastener 30 may create a thread in the plate10 as the fastener 30 is inserted (e.g., threaded) into the hole 22B,thereby locking the fastener 30 to the plate 10.

With reference to FIGS. 9A-9C, the opening 20C includes locking hole 22Cand dynamic compression hole 24C with a more open configuration. Thelocking portion 22C has a textured portion 26C in the form of a taperedthread. This tapered thread may generally correspond to a similartapered thread on the locking fastener 30. The opposite portion 24C ofthe opening 20C is oblong with a ramp 25C milled into the top surface 16of the plate 10 to allow for dynamic compression. As best seen in FIG.9C, the ramp may be partially spherical in shape and extend from the topsurface 16 of the plate 10 and connect to the textured portion 26C. Whenviewed from above in FIG. 9B, the ramp 25C creates a square-like,key-hole, and/or non-hole geometry that sweeps into the tapered threadedlocking hole 22C. This alternative opening 20C also provides for the useof both locking and non-locking fasteners 30, 40 that are able todynamically compress bone and/or lock the plate 10 to the bone.

Turning now to FIGS. 10A-10C, the opening 20D includes locking hole 22Dand dynamic compression hole 24D. These holes 22D, 24D are connected andclose together but are not overlapping. The holes 22D, 24D are separatedby a small portion or sliver of plate material proximate to the lowerportion of the holes 22D, 24D (e.g., at bottom surface 18 of the plate10 and partially extending between the holes 22D, 24D). The lockingportion 22D has a textured portion 26D in the form of a tapered thread.The textured portion 26D extends around almost the entire circumferenceof the hole 22D except where connected to hole 24D. The dynamiccompression hole 24D is elongated and has ramped portions 25D onopposite sides of the hole 24D to receive fastener 40. Thisconfiguration allows for a very close population of holes 22D, 24D onthe plate 10 while giving structural stability at the holes 22D, 24D.

With reference to FIGS. 11A-11C, locking hole 22E and dynamiccompression hole 24E are adjacent, but separate from one another. Theholes 22E, 24E are completely separated from one another by a wall 56 ofplate material. The locking portion 22E has a textured portion 26E inthe form of a tapered thread extends around the entire perimeter of thehole 22E. The dynamic compression hole 24E is elongated and has rampedportions 25E on opposite sides of the hole 24E. This configuration alsoallows for a very close population of holes 22E, 24E on the plate 10while giving options for both locking and/or dynamic compression.

Turning now to FIGS. 12A-12D, an alternative version of opening 20F isprovided. In this embodiment, the hole construct 20F is comprised of atleast three overlapping conical threaded holes in the plate 10. Theopening 20F includes a first, locking hole 22F, a second hole 24F, and athird hole 23F arranged along a longitudinal axis of the plate 10. Thethird hole 23F is the mirror image of hole 24F across the first lockinghole 22F. The conically threaded holes 22F, 23F, 24F may or may not haveparallel axes. Each hole 22F, 23F, 24F may include a textured portion26F, for example, in the form of one or more threaded portions. Thus,the locking fastener 30 may lock to any of the holes 22F, 23F, 24F.Although each of the holes 22F, 23F, 24F are shown in with the texturedportion 26F, it will be appreciated that one or more of the holes 22F,23F, 24F may have a substantially smooth inner portion instead of thetextured portion 26F. The upper part of the hole construct at the firstand second ends of the hole 20F each have a ramped feature 25F (e.g.,adjacent to holes 23F and 24F) to allow for dynamic compression of theplate 10. In addition, the ramped feature 25F may span the three or moreconical holes 22F, 23F, 24F (e.g., around the entire perimeter of theopening 20F).

The non-locking compression fasteners 40 may have a major bone threaddiameter such that the fastener 40 can translate between overlappingholes 22F, 24F, 23F without interference. As best seen in FIG. 12D, thelocking fastener 30 may include a textured area 36, for example, in theform of a thread, configured to engage with the textured portion 26F ofany of the holes 22F, 23F, 24F. The hole geometry of opening 20F can beapplied to bone plates 10 to utilize either fixed angle and/or variableangle locking screws 30 and/or polyaxial non-locking screws 40 that canachieve dynamic compression. This allows surgeons more flexibility forscrew placement, based on preference, anatomy, and fracture location.

Turning now to FIGS. 13A-13B, another embodiment of opening 20G isprovided. This opening 20G may be comprised of one elongate hole or slotextending from the top surface 16 to the bottom surface 18 of the plate10. A locking portion 22G of the opening 20G may include a texturedportion 26G having straight machine threads. The threads may extend morethan 180 degrees to retain the locking fastener 30. A non-lockingportion 24G of the opening 20G may be positioned opposite the lockingportion 22G to complete the opening 20G. The upper part of the opening20G may have one or more ramped features 25G to allow for dynamiccompression of the plate 10. The ramp 25G may span along the entireupper perimeter of the elongated slot 20G or a portion thereof. Thecompression screws 40 may have a major bone thread diameter such thatthe screws 40 are able to translate along the opening 20G withoutinterference.

With reference to FIGS. 14A-14E, alternative embodiments of the lockingfastener 30 may be used with any plate 10. The head portion 32 of thefastener 30 may include a textured area 36 in the form of a thread, forexample, to lock the fastener 30 to the plate 10. The fastener 30 and/orplate 10 may also include one or more mechanisms to prevent back out ofthe fastener 30 from the plate 10. In FIG. 14A, the head portion 32includes at threaded portion 36A (e.g., having straight threads) thatinterface with the plate 10 and the top of the head extends larger thanthe threads. The head portion 32 bottoms out when the fastener 30 isfully inserted and creates preload in the fastener 30, thus locking thefastener 30 rotationally. In FIG. 14B, the head portion 32 includesthreaded portion 36B. The head portion 32 has a constant major diameterwhile the minor diameter is tapered. The thread depth may go to zero atthe top of the head portion 32 of the screw 30. The first few turnssmoothly insert, but as the tapered portion of the male thread engageswith the plate 10, interference occurs, jamming and/or locking the screw30 and preventing backout. In FIG. 14C, a screw thread 36C on the headportion 32, similar to the design in FIG. 14B, except the minor diameterof the screw 30 stays constant while the major diameter of the headportion 32 gets larger toward the top of the screw 30. A similar jammingand locking mechanism results through tightening of the screw 30 in theplate 10. In FIG. 14D, the threaded portion 36D has areas of varyingpitch. In particular, a straight screw thread on the head portion 32 ofthe screw 30 has a similar pitch to that of the plate 10 at the bottomof the head portion 32 of the screw 30. The pitch then increases ordecreases towards the top of the head portion 32, which thereby resultsin jamming of the threads and preventing unwanted backout of the screw30. In an alternative variation of the concept of FIG. 14D, shown inFIG. 14E, the opening in the plate 10 is provided with areas of varyingpitch while the pitch of the threaded portion 36D remains constant. Forexample, the head portion 32 may include a straight thread with aconstant pitch. The upper surface of the plate 10 may include a threadpitch is similar to that of the screw 10, but towards the bottom surfaceof the plate 10, the thread pitch would either increase or decrease tolock the screw 30 to the plate 10.

Turning now to FIGS. 15A and 15B, the plate 10 includes an additionalanti-backout feature. In this embodiment, the plate 10 includescylindrical holes or openings 20H configured to accept either thecompression fastener 40 or the locking fastener 30. Each opening 20H mayinclude a ramped portion 25H extending around a portion or the entireperimeter of the opening 20H to allow for dynamic compression with acompression fastener 40. Each opening 20H may include a cylindricalfeature to provide angular stability with a locking fastener 30. Theopening 20H may also include an angular taper 28 to cause compressivetightening between the locking fastener 30 and the cylindrical opening20H. Each opening 20H has an accompanying blocking screw 46 that can beactuated to block the fastener 30, 40 from backing out. The blockingscrew 46 may extend from a first end at the top surface 16 to a secondend at the bottom surface 18 of the plate 10. The first end of theblocking screw 46 may include a recess sized to receive an instrument torotate the blocking screw 46 from an unblocked position to a blockedposition. The blocked position may include a portion of the blockingscrew 46 covering a portion of the head portion 42 of the fastener 40,thereby further preventing backout of the fastener 40 from the plate 10.

According to yet another embodiment, the plate 10 may include one ormore openings 20 configured to receive the locking fastener 30 havingself-forming threads that work by displacement of the plate material tolock the fastener 30 to the plate 10. Turning now to FIGS. 16-21, thelocking fastener 30 and alternative embodiments of the openings 20 inthe plate 10 are shown. In these embodiments, the locking mechanism ofthe fastener 30 (e.g., bone screw) to the internal fixation plate 10 mayallow for variable angle screw insertion. The fastener 30 may beinserted within an angular cone where the force required to dislodge thehead portion 32 of the fastener 30 is substantially equivalent to theforce required when the fastener 30 is inserted perpendicular to theplate 10. The holes or openings 20 in the plate 10 may be shaped suchthat the fastener 30 may be inserted at different angles. The geometryof the opening 20 is conducive to catching the threads on the headportion 32 of the fastener 30 and to reduce the axial force necessary toinitiate the thread formation.

The locking mechanism includes a fastener 30 having a head portion 32with self-forming threads that displace the plate material. The plate 10may be made of a material softer than the fastener 30 to facilitatedisplacement. For example, the plate 10 may be comprised of titanium,alloys, polymers, or other materials having a lower material hardness(e.g., Rockwell hardness). The fastener 30 may be made of a harderrelative material, for example, comprised of cobalt chrome, tungsten,alloys, or other materials having a higher material hardness.Preferably, the fastener 30 is comprised of a material having a strong,stiff, and high surface hardness which facilitates the thread formingprocess. The forming mechanism works by displacement of material ratherthan removal of the material of the plate 10, thereby minimizingfragments or chips which are created from tapping.

In FIGS. 16A-16B, the locking fastener 30 includes a head portion 32 anda shaft portion 34 configured to engage bone. Although not shown, theshaft portion 34 may be threaded such that the fastener 30 may bethreaded into the bone. The head portion 32 may be tapered (e.g., at anangle of about)20° such that the fit within the opening 20 in the plate10 becomes tighter as the fastener 30 is advanced in to the bone. Thehead portion 32 of the locking fastener 30 includes a textured area 36around its outer surface sized and configured to engage an opening 20 inthe plate 10. The textured area 36 may include threads, ridges, bumps,dimples, serrations, or other types of textured areas. As shown, thetextured area 36 preferably includes a threaded portion extendingsubstantially from the top of the head portion 32 to the bottom of thehead portion 32 proximate to the shaft portion 34. The threads 36 mayrun generally perpendicular to the conical surface of the head portion32. The threaded portion 36 is in the form of self-forming threadsconfigured to displace the plate material and create threads in theopening 20 of the plate 10. The threaded portion has an exaggeratedsharp thread peak to facilitate cutting or forming of the platematerial.

Turning now to FIGS. 17A-20B, alternative versions of the openings 20are shown before being tapped with the fastener 30. Once the fastener 30is inserted, these openings 20 are modified based on the self-formingthreads. The geometry of the openings 20 are conducive to catching thethreads 36 and designed to reduce the axial force necessary to initiatethe thread formation. An upper portion of the hole 20 may be tapered 28,for example, with a conical straight tapered surface cut through the topsurface 16 of the plate 10 for clearance of the head portion 32 of thefastener 30 during off angle insertion. A lower portion of hole 20 mayfurther be tapered 29, for example, with a conical straight taperedsurface cut through the bottom surface 18 of the plate 10 for clearanceof the shaft portion 34 during off angle insertion. The upper taperedportion 28 may be larger, for example, with a larger degree of taperthan the lower tapered portion 29. For example, the upper taperedportion 28 may have a taper in a range from about 60-90°, 70-80°, or72-78°, preferably about 70°, 75°, or 80° whereas the lower taperedportion 29 may have a taper in a range from about 50-70°, 55-65°, or57-63°, preferably about 55°, 60°, or 65°. The upper and/or loweredtapered portions 28, 29 may be substantially conical (e.g., FIGS. 17B,18B, 19B) or may be segmented with more than one section, such as twoseparate conical sections having different diameters or degrees of taper(e.g., FIGS. 20A and 20B).

At the intersection between the upper tapered portion 28 and the lowertapered portion 29 a narrowed central portion may have a texturedportion 26. As described herein, the textured portion 26 may includethreads, ridges, bumps, dimples, serrations, or other types of texturedareas. In the embodiment shown in FIGS. 17A-17B, the textured portion 26includes a windswept cut design comprised of a plurality of shallow cutswhere each cut overlaps the next. For example, the windswept design mayinclude a plurality of threadlike helical cut sweeps. Each cut has asmooth transition into the inner diameter of the hole 20 (e.g., into theupper and lower tapered portions 28, 29). The windswept cuts provide apositive surface for the self-forming threads to cut into, therebyhelping to prevent peeling of the newly formed threads into the plate10.

In FIGS. 18A-18B, the textured portion 26 includes a knurled cut design.A rounded transition between the upper tapered portion 28 and the lowertapered portion 29 (e.g., the two conical cuts) provides a workablesurface for the knurling process as well as a surface for the headportion 32 to be able to roll over during off-axis locking. The knurleddesign may include a plurality of shallow knurled grooves set in adiamond pattern (e.g., about45°) where each cut overlaps the next. Theknurled grooves allow for the self-forming threads to cut more deeplyinto the material and reduce the necessary axial force to begin thethread forming process. FIGS. 19A-19B depict a polygon form cut design.In this design, there is no textured portion at the transition betweenthe upper tapered portion 28 and the lower tapered portion 29. Instead,the narrowed central region has an overall polygonal form such that thehole 20 is neither cylindrical nor conical. The polygonal shape includesa number of sides with distinct linear section of material and roundedcorners around which the form cut is allowed to sweep. For example, thepolygonal shape may be substantially hexagonal (6-sided), heptagonal(7-sided), octagonal (8-sided), etc. The hole 20 may also be representedwithout lobe cuts, as a single concentric ring with the same geometry.

In FIG. 20A, the upper tapered portion 28 includes a conical straighttapered surface cut for clearance of the head portion 32 of the fastener30 during off angle insertion. The upper tapered portion 28 is segmentedto have an upper area with a larger area relative to a lower areaproximate the transition to the lower tapered portion 29 having anarrower diameter. The central area between the upper and lower taperedportions 28, 29, where the thread forming process occurs, includes twopeaks or concentric rings of material (e.g., a superficial ring 60 and adeep ring 62) with a groove 27 being locating in between for materialremoval and thread forming relief. The groove 27 between the rings 60,62 may be angled, for example, in the range of about 40-80°, about50-70°, or about 60°. The superficial ring 60 is of a slightly smallerinner diameter than the deep ring 62, as the superficial ring 60 isresponsible for supporting a majority of the cantilever loads. The deepring 62 provides additional fixation and support during off-angleinsertion as well as additional support during nominal trajectoryinsertion. The lower tapered portion 29 includes a straight taperedsurface that provides clearance for the shaft 34 of the fastener 30 wheninserted off angle.

The embodiment of the opening 20 in FIG. 20B is similar to FIG. 20A, butfurther includes textured portion 26 in the form of a plurality ofhelical swept cuts at the transition between the upper tapered portion28 and the lower tapered portion 29. The shallow helical cuts orwindswept cuts may include a series of cuts at a steep pitch. Thewindswept cuts may be angled, for example, at about 50-70°, or about60°. The same number of cuts may be made in both a clockwise andcounter-clockwise fashion. The cuts may create plateaus of materialprotruding into the opening 20. The resultant geometry provides positivesurfaces for the fastener 30 to cut into, which can dramatically reducethe axial force necessary to lock the fastener 30 to the plate 10. Thusmechanism does not need to rely on bone purchase in order to engage thethreads in the head portion 32 of the fastener 30. The material removedduring insertion of the fastener 30 allows the self-forming threads tocut deeper by removing material which much be formed and reducingfriction between the fastener 30 and the plate 10 during the formingprocess.

FIGS. 21A-21D depict a screw-plate assembly. The assembly, in FIG. 21C,shows the locking fastener 30 placed at an angle, other thanperpendicular, to the upper surface 16 of the plate 10. In FIG. 21D, anon-locking fastener 40 is placed generally perpendicular to the plate10. It will be appreciated that the locking fastener 30 and non-lockingfastener 40 may be oriented at any appropriate angle relative to theplate 10. The section view in FIG. 21C shows the thread engagement withthe plate 10 in which material of the plate 10 is displaced around thethreads of the fastener 30. By using the self-forming threads, thefastener 30 is able to be inserted into the plate 10 at variable anglesand engages with the plate 10 with one-step locking requiring noadditional steps to lock the fastener 30 to the plate 10. The sectionview in FIG. 21D show the compressive, non-locking screw 40 received inthe opening 20, without threadedly locking thereto. The non-lockingscrew 40 may provide for dynamic compression of the bone. Accordingly,the fasteners and openings described herein provide a wide variety ofoptions for the surgeon, thereby providing appropriate locking and/orunlocking capability for dynamic compression depending on the desiredtreatment of the fracture and the bone.

Although the invention has been described in detail and with referenceto specific embodiments, it will be apparent to one skilled in the artthat various changes and modifications can be made without departingfrom the spirit and scope of the invention. Thus, it is intended thatthe invention covers the modifications and variations of this inventionprovided they come within the scope of the appended claims and theirequivalents. It is expressly intended, for example, that all rangesbroadly recited in this document include within their scope all narrowerranges which fall within the broader ranges. It is also intended thatthe components of the various devices disclosed above may be combined ormodified in any suitable configuration.

What is claimed is:
 1. A stabilization system for stabilizing a bone,the system comprising: a bone plate, the bone plate comprising anelongated portion extending along a longitudinal axis and an enlargedhead portion extending from the elongated portion, the bone platecomprising a plurality of through holes; and a drill guide attached tothe enlarged head portion of the bone plate, the drill guide having aplurality of openings that correspond to the plurality of through holeson the bone plate, the drill guide being secured to the bone plate witha fastener extending through an opening in the plate.
 2. Thestabilization system of claim 1, wherein the fastener is in the form ascrew having an enlarged head portion with a recess for receiving adriving instrument and a threaded shaft portion extending from the headportion.
 3. The stabilization system of claim 2, wherein the screw is asingle lead screw.
 4. The stabilization system of claim 1, wherein theopening includes a flange extending partially or completely around theperimeter of the opening.
 5. The stabilization system of claim 4,wherein the flange is recessed into the opening from the top and bottomsurfaces of the plate.
 6. The stabilization system of claim 4, whereinthe flange has top and bottom surfaces that are normal to an axis of theopening.
 7. The stabilization system of claim 4, wherein the flangeoccupies 180 degrees of the opening.
 8. The stabilization system ofclaim 1, wherein the drill guide has an upper surface lower surface, thelower surface being concave and adapted to correspond to a geometry ofthe plate.
 9. The stabilization system of claim 8, wherein the drillguide includes a plurality of projections that extend from the lowersurface of the drill guide.
 10. The stabilization system of claim 9,wherein the plurality of projections are configured to engage withcorresponding openings on the plate.
 11. The stabilization system ofclaim 9, wherein the plurality of projections each include a ledge thatcontacts the lower surface of the plate.
 12. A stabilization system forstabilizing a bone, the system comprising: a bone plate, the bone platecomprising an elongated portion extending along a longitudinal axis andan enlarged head portion extending from the elongated portion, the boneplate comprising a plurality of through holes and an opening comprisinga flange around a perimeter of the opening; and a drill guide attachedto the enlarged head portion of the bone plate, the drill guide having aplurality of openings that correspond to the plurality of through holeson the bone plate, the drill guide being secured to the bone plate witha fastener extending through the opening and contacting the flange ofthe plate.
 13. The stabilization system of claim 12, wherein thefastener is in the form a screw having an enlarged head portion with arecess for receiving a driving instrument and a threaded shaft portionextending from the head portion.
 14. The stabilization system of claim13, wherein the screw is a single lead screw.
 15. The stabilizationsystem of claim 12, wherein the flange is recessed into the opening fromthe top and bottom surfaces of the plate.
 16. The stabilization systemof claim 12, wherein the flange has top and bottom surfaces that arenormal to an axis of the opening.
 17. The stabilization system of claim12, wherein the flange occupies 180 degrees of the opening.
 18. Thestabilization system of claim 12, wherein the drill guide has an uppersurface lower surface, the lower surface being concave and adapted tocorrespond to a geometry of the plate.
 19. The stabilization system ofclaim 18, wherein the drill guide includes a plurality of projectionsthat extend from the lower surface of the drill guide.
 20. Thestabilization system of claim 19, wherein the plurality of projectionsare configured to engage with corresponding openings on the plate.